a. Field of the Invention
The present invention relates to an improved grooved traverse drum for a winder used to produce cheeses or cones.
B. Description of the Prior Art
It is known that the grooved traverse drum (herein after referred to simply as drum) is subject to wear, though slightly, along the various areas of the yarn guide groove, especially in the bottom of the turns at opposite ends of the drum where the yarn turns back as it traverses in the yarn guide groove, since said bottom is most heavily loaded owing to the frequent repetition of rubbing by the yarn, said wear forming a cause of yarn breakage and deterioration in quality.
The conventional practice adopted as a measure of prevention of the above phenomenon has been to apply surface treatment such as alumite treatment or hard chrome plating to the surface of the drum and to the inner surface of the yarn guide groove so as to increase the wear resistance.
Even with such surface treatment applied, however, it has not been possible to avoid such wear when the yarn to be wound is one which itself is highly wear-resistance, such as polyester type synthetic yarn or worsted yarn. Consequently, a surer wear-prevention means has been taken by inserting a member formed of a highly wear-resistant material, e.g., aluminum oxide or titanium oxide, into the particularly severely wearable areas rubbed by the traveling yarn at the turns at opposite traverse ends of the yarn guide groove, so that the yarn travels in contact with the surface of said member.
Examples of previously known drums are shown in FIGS. 4, 4a, 4b, 4c, and 4d of the drawing. These known constructions will now be described with reference to these named Figures. In FIG. 4, a wear-resistant member 1a is horizontally inserted and fixed in position so as to form the bottom of a turn 3' at either traverse end. In FIG. 4a, a wear-resistant member 1a is inserted from the surface of the drum along the lateral surface of a turn 3' at either traverse end and fixed in position so as to form a lateral surface against which the yarn will be rubbed. In FIG. 4b, a wear-resistant member 1a is obliquely inserted along the lateral surface of a turn 3' at either traverse end and fixed in position by an adhesive filler 4. In FIG. 4c, wear-resistant members 1a.sub.1 and 1a .sub.2 are fixed in position so as to form the inner lateral surface of a turn 3' at either traverse end and a wear-resistant member 1a.sub.3 is horizontally inserted and fixed in position so as to form the bottom of the turn 3' at either traverse end. In FIG. 4d, a werar-resistant member 1a is inserted from the surface of the drum along the lateral surface of a turn 3' at either traverse end and fixed in position so as to form a lateral surface and a portion of a bottom against which the yarn is rubbed.
These methods, though more effective for wear prevention than the mere application of a surface treatment procedure as described above, has the following respective disadvantages. The construction shown in FIGS. 4, 4a, and 4b, in which the yarn travels in contact with a portion of the groove bottom as it turns back at the turns at opposite traverse ends, have the disadvantage that the yarn travels as guided by an insertion boundary 5 between the member 1a and the turn 3', resulting in early wear of the relatively soft material suitable for the drum. The methods shown in FIGS. 4c and 4d have the danger of the member embedded in the drum tending to be thrown out under the centrifugal force during rotation, so that it has been necessary to pay careful attention to the operation thereby adding to the cost.
The method shown in FIG. 4d has the further disadvantages that the yarn traveling along the groove bottom causes early wear of a boundary 5 between the wear-resistant member 1a and the relatively soft material 8 suitable for the drum.
FIG. 5 is a partial enlarged sectional view of the drum groove shown in FIG. 4b and serves to better illustrate the disadvantages of the construction. The yarn 6 is wound on a yarn package 9 while being urged against the lateral surface of a wear-resistant member 1a and against the lateral surface of a groove formed of a relatively soft material suitable for the drum, as indicated by an arrow b. In this connection, since the angle of inclination .alpha. of the wear-resistant member 1a with respect to the axis is smaller than the angle of inclination .beta. of the lateral surface of the relatively soft material 8 suitable for the drum, an abnormal force acts instantaneously on the boundary 7 between the wear-resistant member 1a and the relatively soft material 8 suitable for the drum. As a result, a slight amount of wear is produced in the relatively soft material 8 suitable for a drum, forming a cause of deterioration in quality such as yarn breakage and napping.